Means for protecting windows against superficial damage



April 15, 1952 H. H. HUTCHINSON 2,592,805

I MEANS FOR PROTECTING WINDOWS AGAINST SUPERFICIAL DAMAGE Filed Sept.27, 1949 2 Sl-IEETS-SHEET 1 April 15,1952 H. H. HUTCHINSON 2,592,805

MEANS FOR PROTECTING WINDOWS AGAINST SUPERFICIAL DAMAGE 2 smqETs smzs'r2 Filed Sept. 27; 1949 Patented Apr. 15, 1952 MEANS FOR PROTECTINGWINDOWS AGAINST SUPERFICIAL DAMAGE Harry H. Hutchinson, HigherCrumpsall, Manchester, England Application September 27, 1949, SerialNo. 118,018

In Great Britain October 1, 1948 Claims.

This invention relates to the protection against superficial damage ofviewing and lighting windows such, for example, as the vision windows ofthe helmets or work cabinets used in sandor shot-blasting and inspraying operations, as well as the lighting windows or lamp frontsassociated with chambers in which the above operations are carried out.

Depending upon the nature of the flyin particles with which they arebombarded during working hours, such windows rapidly become pitted orfrosted, or obscured by deposit, in such a way that the viewing of theoperation is hindered or the lighting of the working chamber reduced.

When this occurs, and more especially in the case of sandorshot-blasting where the damage to the window cannot otherwise be madegood, the operators onl remedy has been to fit a fresh panel of glass orequivalent material. Even when it is possible, without mechanicalre-polishing, to restore the window to its original transparency, theperiodical attention which is called for involves a considerable loss ofworking time.

The expense and loss of time involved in window replacement isparticularly serious in connection with sandor shot-blasters helmetvisors and work cabinets, which, in order to reduce the risk ofbreakage, are usually made of Celluloid or a thermoplastic resin such asthat known under the registered name Perspex. Glass, although harder andthus less quickly frosted than these materials, cannot be recommendedfor use in the situations aforesaid unless protected by wire gauzewhich, of course, is a further impediment to vision.

The object of the present invention is to provide a simple method andmeans whereby a window may be protected against superficial damage, asdistinct from breakage, and its lightpassing efficiency thus maintained,with a minimum of periodical attention and expense.

The method according to the invention consists in overlaying the exposedsurface of the window with a suitable transparent sheet material andprogressively moving such material to bring undamaged portions thereofinto position over the window.

In carrying the invention into effect, provision is made in the windowframe for guiding a strip of transparent sheet material across theexposed face of the actual window panel, and preferably the frame isarranged to accommodate a supply of such material adjacent one edge ofthe said panel, as well as for clamping'the temporarily-operativeportion of such material against the exposed face of the panel.

The protective sheet material may consist of a thin flexible film of,say, regenerated cellulose, which is capable of being stored in rolledcondition.

In the accompanying drawings:

Fig. 1 is a front view of a viewing window for a sandor shot-blastcabinet, having the transparent panel protected in accordance with thepresent invention,

Fig. 2 is a section on the line 2-2 of Fig. 1,

Fig. 3 corresponds to Fig. 2, but shews an alternative form of cabinetwindow,

Figs. 4 and 5 are views corresponding to Figs. 1 and 2, illustrating theapplication of the invention to a lighting window or lamp front for asandor shot-blast chamber,

Fig. 6 shews the invention applied to the visor of a sandor shot-blastworker's helmet,

Fig. 7 is a section on the line 11 of Fig. 6.

In the construction illustrated in Figs. 1 and 2, the invention isapplied to a viewing window for a sandor shot-blast cabinet, whichwindow will normally comprise a rectangular panel A of Perspex orsimilar material secured between inner and outer metal frame elements,the inner frame B having holes C for screws or bolts whereby it isaflixed to the cabinet wall.

For the purposes of the present invention, the original outer frame isreplaced by a corresponding member D, preferably of aluminium, which isdrilled at or near the corners to fit over studs E projecting from theinner frame B.

The transparent panel A, as well as a third metal frame F adapted forinterposition between the latter and the inner frame B, are similarlydrilled to accommodate the studs E, the window assembly above describedbeing normally clamped tight by manually-operable nuts G on the studs E,with gaskets H of soft rubber or the equivalent at both sides of theintermediate frame F which is preferably of aluminium.

An extension of the frame F beyond one end or lateral edge of thetransparent panel A is formed with an outwardly-facing trough I whichextends parallel to the adjacent edge of the window opening and may havea part-cylindrical base.

Within the trough I, and located therein in any suitable manner, as bymeans of a spindle J supported in the end walls of suchtrough, is arolled web of very thin transparent sheet material K, preferably a filmof regenerated cellulose.

The free end of this film K is drawn over the outer rubber gasket Hbefore the panel A and frame D are applied to the studs E, so that, oncompletion and tightening of the window assembly, such film is clampedin contact with, and completely covers, the inner face of the panel Awhich would otherwise be exposed to bombardment by flying particlesduring use of the cabinet.

In this way, the panel A is completely protected against superficialabrasion, and when the exposed part of the film K becomes itselfobsoured, it is a simple matter to slackenoff the nuts G and, by pullingon the end of such film to draw a fresh section thereof intopositionover the panel A before re-tightening the nuts.

The exposed surface of the composite transparency (consisting of thepanel A and film K) can thus be renewed in a matter of seconds whenevernecessary, and owing to the thinness of the film. a very large number ofsuch renewals can be carried out before the roll becomes exhausted.

Figure 3 illustrates a modified form of window assembly for a sandorshot-blast cabinet, in

which the transparent panel A is set at an angle to the vertical so asto facilitate downward vision.

In this case, the inner frame takes the form of a cast aluminium orother metal box B which is triangular in side elevation and has amarginal facing for attachment to the cabinet wall.

The transparent panel A is located .over a vision opening in the upperinclined face of the box B and is clampedin position by the outer frameD to which pressure is applied by the nuts G.

A rubber gasket H is interposed between the panel-A and the box B andthe protective film K is led upwardly between the panel A ,and thegasket H from the trough I formed in the bov B at alower level.

Figures 4 and 5 show a further embodiment of the invention, as appliedto a lighting window of a sandor shot-blast chamber, the transparent:panel A being adaptedeither to admit daylight or to form a cover for anelectric lamp mounted in the ceiling ofthe chamber.

The inner and outer frames 13*, D in this case, have registeringcircular apertures whose ends are overlapped by the rectangulartransparent panel-A a rubber gasket being interposed at H between suchpanel and the frame B The trough 1 1s formed in the frame 13 and theprotective film K is led therefrom across the inner face of the panel A,which is held in place by the outer frame D and nut G the windowassembly is mounted.

The inner frame B has lateral lugs O for attachment tothe exterior ofthehelmet L, which latter is preferably recessed at P to accommodate thetrough portion I of such frame.

The protective film K in this case .is lead over the outer face of thetransparentpanel A the assembly being clamped by the corner nuts G witha rubber gasket between the panel A and the frame B Preferably the filmKis arrangedto be drawn downwardly so that the used portion thereof does4 not obstruct the worker's vision, and it will be appreciated that theperiodical adjustments of the film K may be effected without any needfor the worker to leave the sandor shot-blast chamher.

It will be noticed that, in all the constructions above described theopening of the film trough is covered by an extension of the outerframe.

If desired, the window assembly may be provided with film-receivingtroughs at opposite edges of the transparent panel, the film being woundas required from a spindle in one trough on to a second spindle in theother trough.

The spindle on which the unused film is stored, or the rolled materialthereon, may be acted upon by a suitable brake, which controls itsrotation.

It will be appreciated that the present invention, besides eliminatingthe expense and loss of time previously involved in window replacementatfrequent-intervals, also has the effect of increasing "productivity,since the utilization of the protection means as above described ensuresthe user working under the best conditions of vision and without eyestrain of any risk thereof.

What-I claim is:

l. The combination with a window, of means for protecting the windowfrom superficial damage caused by impact blows from flying particles,such means including inner and outer superimposed frames having alignedopenings therein, and-means associated with the outer frame forsupporting the window, a web of flexible transparent sheet material ofat least twice the vlength of the window overlying the inner surface ofthe window, and a spindle carried by one of the frames for supportingthe web in rolled condition and bolts which connect the frames and whichcan be tightened so as to clamp the transparent sheet therebetween in anadjusted, fixed position.

2'. Thecombination with a window, of means for protecting the-windowfrom superficial damage caused by impact blows from flying par- "ticles,such means including inner and outer superimposed frames havingregistering openings therein, and means associated with the outer framefor supporting the window, a web of flexible transparent sheet materialof at least twice the length of the window passing between the framesand overlying the inner surface of the window, and a spindle carried bythe inner frame for supporting the web in rolled condition, and

a housing which encloses the web, the superimposed frames having. aclearance therebetween through which the transparent material may bedrawn over-the inner surface of the window and clamping means connectingthe frames to clamp the transparent sheet therebetween in an adjusted,fixed position.

3. The combination with a window, of means for protecting the windowfrom superficial damage caused by impact blows from flying particles,such meansincluding inner and outer superimposed frames havingregistering openings therein, the window being positioned between theframes, a web of flexible transparent sheet material of at least twicethe length of the window passing between the frames and overlying theinner surface of such window, a spindle carried by the inner frame forsupporting the web in rolled condition, a housing carried by the innerframe which encloses the web, and a cover for the housing carried by theouter frame and releasable clamping means connecting the frames, suchmeans when released permitting the transparent sheet to be drawn overthe window to an adjusted, fixed position.

4. The combination with a window, of means for protecting the windowfrom superficial damage caused by impact blows from flying particles,such means including three superimposed frames having registeringopenings therein, the window being positioned between the outermost andthe intermediate frames, a web of flexible transparent sheet material ofat least twice the length of the window overlying the inner surface ofthe window and passing between the two latter frames, a spindle carriedby the intermediate frame for supporting the web in rolled condition,and a housing carried by such frame which encloses the web, a cover forthe housing carried by the outer frame and clamping means connecting theframes to clamp the transparent sheet therebetween in an adjusted, fixedposition.

5. The combination with a workers protective helmet provided with awindow, of means forprotecting the window from superficial damage causedby impact blows from flying particles,

such means including plural superimposed frames having registeringopenings therein, and means associated with the frames for supportingthe window therebetween, a web of flexible transparent sheet material ofat least twice the length of the window overlying the inner surface ofthe window, a spindle carried by the inner frame for supporting the webin rolled condition, a two-part housing carried by the frames whichencloses the web, and bolts connecting the frames to clamp thetransparent sheet therebetween after it has been drawn to an adjusted,fixed position.

HARRY H. HU'TCHINSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,269,584 Downing June 18, 19181,498,767 Vitallo June 24, 1924 1,911,232 Large May 30, 1933

